The present invention relates generally to agricultural combines. It relates particularly to a corn head.
An agricultural combine is a common and well-known machine for harvesting crop materials. Agricultural combines are available in various designs and models to perform the basic functions of reaping crop materials from a crop field, separating the grain from the non-grain crop materials, and discarding the non-grain crop materials back onto the crop field.
A typical combine includes a crop harvesting apparatus, or header, which reaps ripened crop plants from the crop field. The header then feeds the crop materials rearwardly to a threshing system which separates the grain and fine non-grain materials from the coarse non-grain materials. The grain and fine non-grain materials are then directed to a series of moving sieves which further separate the grain from the fine non-grain materials with the aid of a cleaning fan. Finally, the grain is conveyed up to an onboard storage bin, while the coarse and fine non-grain materials are discharged from the rear end of the combine onto the harvested crop field.
One type of header that is used for reaping and gathering crop plants, which is well-known to those skilled in the art of combines, is a corn head. A corn head is a specially designed header that is used for stripping ripened corn ears from the plant stalks. The corn head then feeds the corn ears rearwardly to the combine, where the corn is separated from the cob and the husks. Typically, corn is planted in crop fields in a number of parallel rows which can range from fifteen inches to forty inches in width. The corn head, therefore, includes a number of individual row units that are spaced apart along the width of the corn head so that each row unit operates on a separate row of corn. Corn heads are available in a number of different widths, commonly ranging between four rows and twelve rows in width.
The row units perform the critical task of stripping the corn ears from the stalks. To accomplish this task, a narrow opening is provided that extends between two stripper plates approximately two to three feet in the direction of the corn rows. The narrow opening is wide enough to allow the corn stalks to travel freely through the length of the opening but is narrower than the diameter of the corn ears. Also provided is a set of stalk rolls which are installed under the narrow opening, with one stalk roll positioned on each side of the opening. Each of the stalk rolls includes a cylindrical body with spiral vanes that extend outward from the cylinder""s surface. The stalk rolls then rotate around an approximately horizontal axis which is in a plane parallel to the corn rows and the narrow opening. Therefore, when the corn plants enter the front end of the narrow opening, the rotating spiral vanes of the stalk rollers grab the corn stalks and pull the stalks downward. As the corn stalks are pulled down through the narrow opening the wider corn ears are stripped from the stalk by the stripper plates. Gathering chains which include extended fingers then feed the stripped corn ears rearwards toward a gathering conveyor.
One problem with this method of stripping corn ears from the stalks is the inability of the combine operator to consistently maneuver the combine accurately enough to align the narrow opening to receive the rows of corn. This problem is typically solved with a funneling system that directs the corn plants to the narrow opening when the row unit and corn row are misaligned. Typically, this funneling system includes a divider that is made from sheet metal or plastic and which forms an elongated shield between adjacent row units. The divider, therefore, extends forward from the row units and travels between the rows of corn. The divider further includes a pointed forward end and an expanded rear end that spans between adjacent narrow openings. Thus, as the rows of corn plants contact the sides of the divider because of misalignments between the corn head and the corn rows, the corn plants are redirected towards the narrow opening in a funnel-like manner.
Typically, an adjustment mechanism is provided for adjusting the height of the divider to allow the divider to effectively funnel corn plants of various heights and conditions. For example, in some cases the corn is broken down by wind prior to harvest so that the crop stalks are lying near the ground. In this case the dividers can be adjusted downwards to allow recovery of the fallen crops. In extreme cases the divider is lowered all the way down near the ground surface so that the bottom of the divider skims the ground. In other cases when the corn is standing tall, the dividers can be raised several feet off the ground to minimize the portion of the corn stalks that must be fed through the stripper plates.
Several height adjustment mechanisms are known to the art. One known mechanism includes a tension shaft assembly that extends from the front end of the divider to a rearward support structure. This mechanism uses a series locking holes and a lock pin to vary the length of the shaft assembly, which correspondingly adjusts the height of the divider. This mechanism has the disadvantage, however, of providing only a limited number of height adjustments based on the number of holes provided and their spacing.
Another adjustment mechanism that is known to the art is a tension chain assembly with an L screw. In this assembly the chain includes a number of links and extends between the front end of the divider and a rearward support. The L screw is attached between one end of the chain and the front or rear connecting point. The length of the assembly, and consequently the height of the divider, is then adjusted in a two step process. Accordingly, the height is first roughly set by removing or adding links of the chain to the tension length. Next, the height can be fine tuned by adjusting the L screw inward or outwards. This adjusting process is time consuming, however, and can require repeated trials to arrive at the desired height. Another disadvantage of this mechanism is the existence of a loose flopping member that can become entangled with the fingers of the gathering chain. This situation can occur when the dividers are set close to the ground and a raised object is struck by the bottom of a divider. The divider will then buckle upwards around a rearward pivot connection which then releases the tension from the chain. Once this happens the loose chain can flop around and become entangled in the gathering chain. The entanglement such as this will damage the tension chain and the gathering chain and will require repairs before harvesting can proceed.
Another problem with dividers is the long length of the divider that extends past the front end of the row units. Typically, the dividers extend approximately three to four feet in front of the row units in order to effectively funnel the crop rows. This extended length, however, is a disadvantage when the combine is being transported from location to location or when the corn head is being shipped from the manufacturer. During farm transportation this extended length creates a collision hazard, which the combine operator must be attentive to. In addition, the manufacturer""s shipping costs are increased because of the extended dividers. Typically, shipping costs are calculated based on the volume of the product being shipped. Manufacturers, therefore, regularly try to reduce these costs by minimizing unnecessary extending portions which require additional shipping volume.
Accordingly, it is an object of the invention to provide a tension assembly for the support structure of a divider that can buckle upwards along a predetermined and predictable travel path when the divider strikes ground objects.
It is a further object of the invention to provide a clearance opening through a lateral hood support for the tension assembly.
It is still a further object of the invention to provide a height adjustment mechanism with infinite adjustments within a range.
It is still a further object of the invention to provide a retention pin along the front end of the support structure that can lock the front end of the divider in a rearward transport or service position.
It is still a further object of the invention to provide a shipping position for the support structure that minimizes the portion that extends beyond the front end of the row units.
The support structure includes a pivot support member attached to the corn head, with longitudinal support members pivotally attached to the pivot support member. A cross support member is attached to the forward end of the longitudinal support members. The tension assembly includes a first tension member and a second tension member which are pivotally attached to each other. The rear end of the first tension member is pivotally attached to the pivot support member, and the front end of the second tension member is pivotally attached to the cross member. The lateral hood support is installed across the top of the first tension member and includes a clearance opening to allow travel clearance for the first tension member. Additionally, the first tension member is bent downward to provide further travel clearance. A retention pin is included along the front end of the support structure which can lock the divider in a rearward position to allow a secure transport or service position.